Transcript Why Study the Autonomic Nervous System

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Why Study the Autonomic Nervous System?
Medicinal
Chemistry
Pathophysiology
Therapeutics
ANS
Disease State
Management
Pharmacology
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Organization of The Nervous System
Central Nervous System
Autonomic Nervous System
Sympathetic
Peripheral Nervous System
Somatic Nervous System
Parasympathetic
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How do we define neuron types in the ANS?
Parasympathetic
O
C
CH3
Sympathetic
HO
CH3
CH2
O
CH2
N
CH3
HO
CH
Acetylcholine CH3
NH 2
OH
Norepinephrine
HO
CH3
H3C
CH2
O
CH2
Muscarine
N
(Noradrenaline)
CH3
HO
CH3
HO
N
CH3
N
CH
CH2
OH
Epinephrine
(Adrenaline)
Nicotine
NH
CH3
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Parasympathetic Ganglionic Synapse
Acetylcholinesterase
Na+
aba
ACH
Action Potential
Na+
Preganglionic neuron
Nicotinic
Receptor
Postganglionic neuron
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Parasympathetic Organ Synapse
Acetylcholinesterase
Effector
Organ
Na+
K+
G
Action Potential
ACH
Muscarinic
Receptor
Postganglionic neuron
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Summary of parasympathetic neurons
and synapses
Preganglionic neurons



Long
Synapse with postganglionic neurons at or near organ
Release acetylcholine (ACH) to activate nicotinic receptors on
postganglionic neurons
Postganglionic neurons



Short
Synapse on the target organ
Release acetylcholine (ACH) to activate muscarinic receptors on
the target organ
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Sympathetic Ganglionic Synapse
Acetylcholinesterase
Na+
aba
ACH
Action Potential
Na+
Preganglionic neuron
Nicotinic
Receptor
Postganglionic neuron
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Sympathetic Organ Synapse
Effector
Organ
Na+
Action Potential
NE
Adrenergic
Receptor
Postganglionic neuron
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Summary of sympathetic neurons
and synapses
Preganglionic neurons



Short
Synapse with postganglionic neurons near spinal cord
Release acetylcholine (ACH) to activate nicotinic receptors on
postganglionic neurons
Postganglionic neurons



Long
Synapse on the target organ
Release norepinephrine to activate adrenergic receptors on target
organs
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Exceptions in the sympathetic nervous system:

Sweat glands:
» Postganglionic neurons
»
involved with stress-related
excretion release
norepinephrine (“sweaty
palms”)
Postganglionic neurons
involved with
thermoregulation release
acetylcholine
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Exceptions in the sympathetic nervous system:

Kidneys:
» Postganglionic neurons to the
smooth muscle of the renal
vascular bed release dopamine

Adrenal gland:
» Preganglionic neurons do not
»
»
synapse in the paraverterbral
sympathetic ganglion
Preganglionic neurons synapse
directly on the adrenal gland,
release acetylcholine, and
activate nicotinic receptors on
the adrenal gland
Adrenal glands release
epinephrine into systemic
circulation
Most postganglionic sympathetic
neurons release what
neurotransmitter?
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How do drugs influence the ANS?

Mimic or block the effects of the two primary neurotransmitters,
Acetylcholine and Norepinephrine/Epinephrine

Drugs that mimic neurotransmitters are referred to as “receptor
agonists”
 These drugs activate receptors

Drugs that block neurotransmitters are referred to as “receptor
antagonists”
 These drugs block the endogenous neurotransmitters from
activating receptors
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Classification of drugs affecting the ANS

Parasympathetic nervous system
Mimic acetylcholine = cholinergic = muscarinic agonists = parasympathomimetic
Block acetylcholine = anticholinergic = muscarinic antagonist = parasympatholytic

Sympathetic nervous system
Mimic norepinephrine = adrenergic = adrenergic agonist = sympathomimetic
Block norepinephrine = antiadrenergic = adrenergic antagonist = sympatholytic